Booking.com - Find your next stay. Search deals on hotels, homes, and much more...

Meetup - Helps groups of people with shared interests plan events and facilitates off line group meetings in various localities around the world.

Tripadvisor - The Tripadvisor mobile app is available for the Android and iOS platforms. It can be used to create reviews of hotels, restaurants, and to chat with other travelers on Tripadvisor forums.

Event Hunt - Startups and Tech Events Curated By Locals

Sygic Travel Maps - Itinerary planner for independent travelers

Eventbrite - Discover Great Events or Create Your Own & Sell Tickets